Effects of Lactococcus lactis on colorectal cancer in various terms: a narrative review

Abstract

Introduction: Colorectal cancer is one of the most common cancers with an increasing number of cases. Various studies have found an association between the gut microbiota balance and colorectal cancer incidence. Lactococcus lactis is a probiotic bacterium found in fermented foods, particularly yogurt and cheese. This probiotic has been shown to reduce various anti-inflammatory and pro-inflammatory agents that trigger cancer, such as interleukin (IL)-6, IL-18, tumour necrosis factor-alpha (TNF-α), and natural killer (NK) cells. Methods: Full-text articles and original research published in the last ten years were used as references, and “Lactococcus and colorectal cancer” as keywords. The reference search is on several databases, such as PubMed, ScienceDirect, ProQuest, and Nature. Searching results obtained eleven articles. Discussion: Lactococcus lactis does have a perfect role in suppressing cancer cells. Lactococcus lactis has anti-proliferative effects associated with decreased cyclin D1 expression in SW480 cell lines, decreased NK cells, reduced cancer cell viability, decreased IL-8 levels, and decreased IL-6. Conclusion: Lactococcus lactis contains nisin, which can suppress various gene, protein, and cytokine expressions that play a role in cancer cell growth. Probiotics can inhibit colorectal cancer without significant side effects.